Helmets for head protection are worn in a variety of environments and for various purposes. Helmets are often secured to a wearer's head by a flexible chin strap. The chin strap may include multiple segments of flexible strap material that are secured at either side of the helmet and pass below the chin, where the segments are releasably joined. In some helmets the strap segments on either side of the helmet are attached to the helmet at two positions, in front of and behind the wearer's ear. When joined, the two strap segments form a single strap that may be adjusted in length. Many of the available approaches to connecting the strap segments are cumbersome and lack security. In some cases, for example, the wearer must pass one end of the strap through a buckle or a pair of “D-rings” with a return loop, making it difficult to quickly remove the helmet in an emergency. In other cases, a quick release “snap” lacks security due to the possibility of accidental release. Two-finger release mechanisms, while more secure, typically attach to the ends of the strap segments and thus require intervening length in line with the straps. This makes it difficult to place the fastener near the chin, which can be important to the stability of the helmet.
Conventional helmet straps may also be difficult to adjust. If only a single strap is provided on each side of the helmet, for example, the adjustment can be made at the buckle where the straps are joined. If the chin strap has connections at two positions on each side of the helmet, however, the two separate strap segments each need adjustment for length, but generally have no convenient buckle or termination to accommodate such adjustment. A typical approach for adjusting the length of these strap segments is to fix one end of the strap and loop the free end through a buckle or loop, returning it to a ladder-lock adjustment mechanism positioned along the length of strap. By pushing more or less of the free end through the ladder lock, the length of a strap segment is altered. The geometry of this solution dictates that for each inch of length adjustment, the free end must move two inches. The free strap end that extends beyond the ladder lock may be secured with an additional component such as a clasp, or in some designs the wearer can adjust the position of the ladder lock along the strap segment to minimize the length of the exposed strap. In any case, the result is that adjusting the length of helmet straps is neither fast nor convenient and may require removing the helmet and making multiple adjustments, repositioning the ladder lock, and trying the helmet again for proper fit.
While adjustment theoretically is needed only when the helmet is first acquired, in practice the wearer may wish to adjust the tightness of the straps according to circumstances. In active situations, for example, especially if additional accoutrements such as night-vision goggles are attached to the helmet, the wearer may wish the straps to be tighter than normally required.